The biological requirements for vascular prostheses must include considerations of the tissue-material interface on the exterior of the device as well as the blood-material interface at the luminal surface. As improvements in blood compatibility increase the useful lifetime of these implants, the nature of the soft tissue response becomes more relevant to the overall clinical success of these devices. This project has been designed to develop an in vitro model for the cellular interactions that occur during the soft tissue response, and to use this model to evaluate the contribution of specific material properties. Surface charge, surface polar effects, surface modulus and surface topography will be systematically varied by modification of woven and knitted fabrics currently in use as vascular grafts. The biological model will include: 1. Primary and established lines of normal fibroblasts. 2. Neutrophil and macrophage cells from peritoneal exudates. 3. Assays for the rate and extent of cell adhesion, enzyme release kinetics from neutrophils and the production of collagen by fibroblasts growing on the test materials. 4. Time-lapse and scanning microscopy of cellular interactions at the substrate interface.